Measuring the temperatures that a turbo machinery component (i.e., blades, vanes, rotors, wheels, casings, bolts, buckets, nozzles, combustion hardware and/or shrouds) has been exposed to or experienced is important to verify the design of the turbo machinery. Measuring the temperature is also useful to estimate metallurgical changes in the component, estimate the remaining operational life of the component, optimize inspection intervals, and regulate operational conditions. Turbo machinery includes but is not limited to, gas turbines, steam turbines, jet-engine turbines, and other turbine assemblies. Components subjected to extreme environments are particularly susceptible to degradation, the extent of which depends on a number of factors, such as the creep rate, rupture stress, stress/strain amplitude of cyclic loading, corrosion and/or erosion rate, and thermal mechanical fatigue, among other things. In some cases, such as when the component is exposed to high temperatures for prolonged periods of time, the component material undergoes metallurgical changes (e.g., chemistry, microstructure, etc.) that reduce the component's reliability and durability. The degree of effect that these factors may have depends on the operational working temperatures of the component. Therefore, the temperatures that are experienced by a component are an important parameter governing the life of such components, as is the time that is spent at these temperatures. Life assessment procedures have been developed to estimate the remaining operational life of such components based on the operating temperatures that these components have been exposed to or have experienced, and the time these components have spent in operation.
Currently, there are both destructive and non-destructive systems and methods for estimating the temperatures that a component has been exposed to or has experienced during operation of turbo machinery. Destructive systems and methods involve cutting up and destroying the component so that the characteristic metallurgical changes in the component can be investigated, and the time-temperature relationship can be estimated therefrom. Non-destructive systems and methods that have been used to estimate the temperatures that hot-gas-path components in gas turbines have been exposed to or have experienced include using thermocouples, pyrometers, eddy current sensors and/or temperature probes, among other things.
The current systems and methods for estimating temperatures have significant drawbacks: 1) many systems require a laborious procedure; 2) many systems use a complex arrangement of sensors; 3) many systems require components that are unable to sustain long hours at the high temperatures that turbo machinery components experience; 4) many systems include components that many are not resistant to the hostile environment (i.e., oxidation, corrosion) that components experience; 5) many systems are destructive to the components themselves, and/or 6) many systems are not suitable for moving parts.
Therefore, a simpler, more reliable, easier to use, non-destructive system and method that will allow the temperatures that components are exposed to be measured that does not suffer from the above drawbacks is desirable in the art.